qpid-jms-client/src/main/java/org/apache/qpid/jms/jndi/LazyCreateContext.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.qpid.jms.jndi;

import javax.naming.NameNotFoundException;
import javax.naming.NamingException;

/**
 * Allows users to dynamically create items
 *
 * @since 1.0
 */
public abstract class LazyCreateContext extends ReadOnlyContext {

    private static final long serialVersionUID = 5131341840091473967L;

    @Override
    public Object lookup(String name) throws NamingException {
        try {
            return super.lookup(name);
        } catch (NameNotFoundException e) {
            Object answer = createEntry(name);
            if (answer == null) {
                throw e;
            }
            internalBind(name, answer);
            return answer;
        }
    }

    protected abstract Object createEntry(String name);
}